Abstract
Background: Magnetocardiography (MCG) is a non-contact mapping technique to record cardiac action currents. The Master's two-step electrocardiogram (ECG) test is a simple exercise method for screening coronary artery disease (CAD), but it is inadequate concerning the sensitivity. Our aim was to develop a new screening method using multichannel MCG instead of ECG. Methods: Thirty subjects (aged 54 ± 16 years, 27 males), 17 of whom had CAD confirmed by coronary angiography, underwent the Master's exercise ECG test. After the exercise, MCG signals were acquired every minute during recovery with a 64-channel MCG system (MC-6400, Hitachi Ltd). We integrated tangential components of the MCG signals within QRS (during 20, 40, 80, and 120 ms centering on R-wave peak) immediately after exercise (Iex) and 5 minutes after exercise (Irec). The exercise-induced change of currents [(Iex-Irec)/Irec] was determined and normalized for each channel, and the maximal change among 64 channels, maximal QRS integral change, was used as a diagnostic index for myocardial ischemia. Results: The maximal QRS integral change during 40 ms was significantly higher in the CAD group than in the control group (0.81 ± 0.51 vs. 0.36 ± 0.19, p <0.01). A sensitivity and specificity for predicting CAD by the change > 0.44 were 82% and 85%, respectively, yielding a diagnostic accuracy of 83%. The conventional Master's ECG test identified the CAD patients with a diagnostic accuracy of 63% (sensitivity 47%, specificity 85%). Conclusion: The Master's two-step exercise test with a 64-channel MCG system showed the high diagnostic accuracy, despite of non-contact recording and simple exercise. The magnetic field in the depolarization process has the potential to detect the subtle myocardial ischemia induced by exercise.
| Original language | English |
|---|---|
| Pages (from-to) | 124-132 |
| Number of pages | 9 |
| Journal | Basic Research in Cardiology |
| Volume | 98 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Mar 2003 |
| Externally published | Yes |
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Keywords
- Coronary artery disease
- Magnetic field
- Magnetocardiography
- Myocardial ischemia
- QRS complex
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine
Cite this
A new screening method to diagnose coronary artery disease using multichannel magnetocardiogram and simple exercise. / Kanzaki, Hideaki; Nakatani, Satoshi; Kandori, Akihiko; Tsukada, Keiji; Miyatake, Kunio.
In: Basic Research in Cardiology, Vol. 98, No. 2, 03.2003, p. 124-132.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - A new screening method to diagnose coronary artery disease using multichannel magnetocardiogram and simple exercise
AU - Kanzaki, Hideaki
AU - Nakatani, Satoshi
AU - Kandori, Akihiko
AU - Tsukada, Keiji
AU - Miyatake, Kunio
PY - 2003/3
Y1 - 2003/3
N2 - Background: Magnetocardiography (MCG) is a non-contact mapping technique to record cardiac action currents. The Master's two-step electrocardiogram (ECG) test is a simple exercise method for screening coronary artery disease (CAD), but it is inadequate concerning the sensitivity. Our aim was to develop a new screening method using multichannel MCG instead of ECG. Methods: Thirty subjects (aged 54 ± 16 years, 27 males), 17 of whom had CAD confirmed by coronary angiography, underwent the Master's exercise ECG test. After the exercise, MCG signals were acquired every minute during recovery with a 64-channel MCG system (MC-6400, Hitachi Ltd). We integrated tangential components of the MCG signals within QRS (during 20, 40, 80, and 120 ms centering on R-wave peak) immediately after exercise (Iex) and 5 minutes after exercise (Irec). The exercise-induced change of currents [(Iex-Irec)/Irec] was determined and normalized for each channel, and the maximal change among 64 channels, maximal QRS integral change, was used as a diagnostic index for myocardial ischemia. Results: The maximal QRS integral change during 40 ms was significantly higher in the CAD group than in the control group (0.81 ± 0.51 vs. 0.36 ± 0.19, p <0.01). A sensitivity and specificity for predicting CAD by the change > 0.44 were 82% and 85%, respectively, yielding a diagnostic accuracy of 83%. The conventional Master's ECG test identified the CAD patients with a diagnostic accuracy of 63% (sensitivity 47%, specificity 85%). Conclusion: The Master's two-step exercise test with a 64-channel MCG system showed the high diagnostic accuracy, despite of non-contact recording and simple exercise. The magnetic field in the depolarization process has the potential to detect the subtle myocardial ischemia induced by exercise.
AB - Background: Magnetocardiography (MCG) is a non-contact mapping technique to record cardiac action currents. The Master's two-step electrocardiogram (ECG) test is a simple exercise method for screening coronary artery disease (CAD), but it is inadequate concerning the sensitivity. Our aim was to develop a new screening method using multichannel MCG instead of ECG. Methods: Thirty subjects (aged 54 ± 16 years, 27 males), 17 of whom had CAD confirmed by coronary angiography, underwent the Master's exercise ECG test. After the exercise, MCG signals were acquired every minute during recovery with a 64-channel MCG system (MC-6400, Hitachi Ltd). We integrated tangential components of the MCG signals within QRS (during 20, 40, 80, and 120 ms centering on R-wave peak) immediately after exercise (Iex) and 5 minutes after exercise (Irec). The exercise-induced change of currents [(Iex-Irec)/Irec] was determined and normalized for each channel, and the maximal change among 64 channels, maximal QRS integral change, was used as a diagnostic index for myocardial ischemia. Results: The maximal QRS integral change during 40 ms was significantly higher in the CAD group than in the control group (0.81 ± 0.51 vs. 0.36 ± 0.19, p <0.01). A sensitivity and specificity for predicting CAD by the change > 0.44 were 82% and 85%, respectively, yielding a diagnostic accuracy of 83%. The conventional Master's ECG test identified the CAD patients with a diagnostic accuracy of 63% (sensitivity 47%, specificity 85%). Conclusion: The Master's two-step exercise test with a 64-channel MCG system showed the high diagnostic accuracy, despite of non-contact recording and simple exercise. The magnetic field in the depolarization process has the potential to detect the subtle myocardial ischemia induced by exercise.
KW - Coronary artery disease
KW - Magnetic field
KW - Magnetocardiography
KW - Myocardial ischemia
KW - QRS complex
UR - http://www.scopus.com/inward/record.url?scp=0037343941&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0037343941&partnerID=8YFLogxK
U2 - 10.1007/s00395-003-0392-0
DO - 10.1007/s00395-003-0392-0
M3 - Article
C2 - 12607134
AN - SCOPUS:0037343941
VL - 98
SP - 124
EP - 132
JO - Basic Research in Cardiology
JF - Basic Research in Cardiology
SN - 0300-8428
IS - 2
ER -